Amplifying current variations.



E. WEINTRAUB & M. C. A. LATOUR.

AMPLIFYING CURRENT VARIATIONS.

APPLICATION IIL'ED NOV. 26, 1907.

1,041,210, Patented Oct. 15,1912.

3 v Z /Z-/" g8 umglm n 6 J- /0 Witnesses: Inventors UNITED STATES 1 PATNT oErroE.

EZECHIEL WEIN'IRAULB, or SCHENECTADY, EW YORK, AND MARIUS o. A. LATOUR,or PARIS, FRANCE, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CoRPonArroNor NEW YORK.

AMFLIFYING CURRENT VARIATIONS.

Patented Oct. 15,1912.

Application filed November'26, 1907. Serial No. 403,868.

To all 'whom it may concern:

Be it known that we, EZECHIEL WEIN- TBAUB, a citizen of the UnitedStates, resid- France, have invented certain new and useful Improvementsin Amplifying Current Variations,of which the following is aspecification.

less telegraphy, and in fact in any situation where weak signals orcurrent impulses are to be registered or detected, it is desirable tohave means which will amplify these current impulses or signals toproduce amplified variations of current responsive to the signalcurrents.

Our present invention aims to provide a receiving device or system whichwill operate in response to small current variations to produce verygreatly magnified currents or impulses. The principle of our inventiondepends upon the fact that in the neighborhood of the polarizationvoltage of a mercury are or similar device, a small mcrease of"impressed. elcctromotive force I causes the leakage current, ordischarge, in

such a device to change into the form of an arcwlth a correspondingenormous morease In current. As 1s well-known, an are (118- charge ischaracterized by a comparatively low potential drop at the electrodes,and by a high current value. By thus utilizing the signal currents orother weak impulses of current, the voltage in the local circuit, whichvoltage is normally adjusted in the region of the polarization voltageof they lamp, is caused by the superposed voltages due to the variablecurrents to exceed the polarization voltage and to produce arcdischarges with correspondingly large current variations. These largecurrent variations may readily be observed by the flashes of light inthe mercury vapor device, 6r may be utilized to operate a recordingdevice,. or for any other desired purpose.

The features of novelty which characterize our invention are set forthwith particularity in the appended claims. The inven tion itself,however, will be better understood by reference to the followingdescription taken in connect-ion with the accompanying drawings whichrepresent diagrammatically one embodimenhof our invention.

though aswitch may be From what we have already said it will be evidentthat our new receiving device or current amplifying device, takingadvantage as it does of the sensitive condition of the mercury vaporlamp or tube at or about the polarization voltage, must be such aform-of device as will produce an are discharge as distinguished fromaleakage or sort of Geissler tube discharge, immediately the polarizationvoltage of the tube is sufli In the arts of telephony, telegraphy,w1reciently' overcome. For this purpose we may use any one of a largevariety of forms of apparatus. We have, however, indicated in thedrawings, for purposes of illustration, a form ofmercury arc devicesuitable for the purpose..- This may consist of a highly evacuatedglass. envelop or container 1. This-container is provided withelectrodes which form the seats, respectively, of two current paths, onea continuously maintained auxiliary arc, and the other a leakage ordischarge path through the instrumentality of which the desired currentvariations are produced. For these two discharge paths a negativeelectrode 2 of mercury is provided as a common cathode. A platinum wireprojects above the surface of the electrode at 3 in order to render thecathode spot of the arc stationary, and also to permit the current inthe container to be run at a low value." An electrode 4 of suitable ma-.terial, such as artificial graphite, is locatedabove the cathode2,andbetween itand the cathode an arc is constantly maintained from somesuitable source of current, in this case a direct current generator orbattery indicated conventionally at 5. This source of current 5 may beconnected through a resistance 6 with the electrode 4.

In order to start the are an auxiliary electrode 7 of mercury, locatedadjacent to the cathode 2, is provided, and is connected also to thesource 5. When the tube or container l-is shaken so that the mercury ofthe d electrodes 2 and 7 forms a temporary connection, an arcis thusstarted and this arc then starts the main arc to the electrode 4. Aresistance, such as 8, is provided so as to cause the are between 7 and2 to go out as soon as the main arc between 4 and 2 starts,

used in place thereof if desired.

The path in'which the desired current variations are produced isprovided by means of an electrode or anode 9, located in a 1 vice 11,which may be'of any desired form, or may be omitted altogether, asecondary be'readily understood, receievs the weak signal currents orthe like from the appropriate and in the case of a telegraph ortelephone yery smallvalue.

. current is received by the primary 13 of'the .sation is producedin thesecondary 12 and tery or source'lO, produce a momentary voltbranch ofthe'tube or container 1 and it is between this electrode 9 and thecathode 2 that the phenomena take place which permit us to-obtaingreatly magnified current variations in response to weak signals orcurrent fluctuations or pulsations. To se cure the desired results, weprovide a local circuit including the anode 9 and the cathode 2. Thislocal circuit includes a battery or other source of readily adjustableelectromotive force 10, a current-indicating de-' winding 12 of a,transformer the primary 13 of which receives the weak signals, and aresistance 14 for limiting the current flow.

source, as for example in a wireless telegraph system, from the antennaeor the like,

system, from the transmission line or circuit.

In the operation of our new receiving device or current amplifier, thespace between the anode 9 and the cathode 2 must always be in conditionso that an arc will form as soon as the voltage impressed upon saidelectrodes is suflicient'to maintain an are. It is for this purpose,therefore, that an auxiliary arc is kept constantly in existence betweenthe auxiliary 3.110(164 and the cathode 2 by means of current from thesource 5. Under these conditions, the battery 10, or. other source ofcurrent, will always produce a flow of current between the anode 9 andthe cathode 2, but the character of thiscurrent flow will depend uponthe magnitudeof the voltage of the source 10. If the voltage of thesource is such that the difference of potential between the anode 9 andthe cathode 2 is substantially equal to or less than the polarizationvoltage, that is to say, the voltage at which the leakage discharge isabout to change into .an arc discharge, there willbe merely a sort ofleakage current between the anode 9 and the cathode 2 of relatively"When, now, a current pulsation or Si alreceiving transformer, acorresponding pulthis is superposed, so to speak,up'on the voltage ofthe battery 10. These voltage pulsationsin the, secondary 12, or atleast those portions of the pulsations of the right po larity, b'eingadded to the voltage ofthe batage of a magnitude greater than thepolaritube 1, and thereby cause the leakage dis-- charge, whichcontinually takes'place in the. tube 1 between the anode 9 and thecathode 2, tov change intoan arc discharge. These are discharges, ofcourse, are only momentary depending upon the duration of the voltageimpulses in the secondary 12, but when they occur thereis an enormousincrease of current in the local circuit of the. secondary due to thegreatly decreased resistance of the tube 1 'to the passage of currentbetween the electrodes mentioned. These current impulses or amplifieddischarges in the tube 1 may be very readily observed by noting theflashes of light in'the tube itself without any other indicating meansbeing required. If desired, however,

What we claim as new and desire to secure by Letters Patent of theUnited States.

1. A current receiver consisting of an evacuated envelop, a cathode ornegative electrode, means for constantly exciting said electrode, ananode cooperating with said cathode, means adjusted to normally impressbetween said anode and cathode a voltage less than the polarizationvoltage of an'arc discharge, and means responsive to current variationsfor momentarily raising the voltage between said electrodes above thepolarization volt-age.

2. The combination of electrodes between which an arc may be, produced,means for enabling such an arc to be produced whenever a voltage inexcess of the polarization voltage of an arc is applied tosaidelectrodes, means for impressing on sald electrodes a voltageapproximating the polarization voltage, a source of current variations,and

means for augmenting said voltage in responseto said current variationsto raise the same above the polarization voltage and thereby produceanare between said. electrodes.

3. The 'ombination of an evacuated envelop containingelectrodesadapted'to form the seat of anarc discharge, means forconstantly exciting the cathode or negative electrode, means forimpressing .a substantially constant voltage on said electrodes, andmeans for superposing voltage impulses to produce corresponding arcdischarges between said electrodes.

4. The method of amplifying current variations which consists inimpressing upon electrodesa voltage just insufficient to produce an arcdischarge, and augmenting-said Voltage at recurrent intervals to ,avalue sufroduce an arc discharge-in ree fiuctuatlons of a var ablecurcurrents or impulses, which consists in impressing uponelectrodesbetween which an arc may be produced a voltage insuflicient tomaintain such an arc, and recurrent-1y augmenting said voltage to thearcing voltage in response to the variable currents or impulsest0produce corresponding arcdischarges between said electrodes. n 6. Themethod of amplifying current ariations which consists in maintainingnormally between electrodes :1 weak discharge or current flow of thenature of a leakage current, and. causing this leakage current to changeinto an arc in response to signal currents or other impulses.

7. The method of producing amplified current waves or fluctuationsresponsive to, varlable currents, which consists in malntaining betweensuitable electrodes a dis,- charge normally of the nature of al'caka'gecurrent, and causing this leakage current to develop into an arc inresponse to variable currents or impulses.

v In witness whereof, WEINTRAUB has hereunto set his hand thisllthday ofOctober,

1907, and-LAToUR has hereunto set his hand thi's,,9th day of November,1907. g

EZECHIEL VVEINTRAUB- MARIUS C..A. 'LATOUR. Witnesses to Weintraub:

HELEN Onronn, FRA K J. Donn. Witnesses to Latour:

DEAN tB.-"MABQN, ALMA DALMA MARSHALL.

